Code reading is effected in a conventional manner by scanning with the help of a semiconductor laser or similar techniques. Optoelectronic devices (photodiodes, charge coupling devices or CCD, etc.) convert the information which they read, and which appears under the shape of light intensity variations, into electronic signals which are stored and are utilized in situ, or still transmitted to a remote central computer system. Generally, the reading instrument includes a display member such as a liquid crystal display, a keyboard for entering data or programming instructions, as well as information processing and data storage circuitry.
The most recent bar code reading apparatuses are built around a microcomputer architecture; they can be coupled to a central computer system in various ways: hertz waves, wired link, modem, optical (infrared) channel, and so on. They can record a large number of data, which data can concern both information being read from these bar codes and various pre-recorded information and/or instructions.
Apparatus of this type is in particular used for preparing parcels according to a customer order, by loading those products, to be delivered, which are available in a storage installation provided for various items. Within the scope of the invention, the expression "storage installation" relates to any type of warehouse for logistically distributing various products, items, goods, pieces or objects.
As schematically illustrated in FIG. 1, appended to the present description, a distribution warehouse 1, when it is complex, includes several distinct areas, for instance the following areas:
a reception area Z1 intended for unloading vehicles, checking the received goods, identifying products and grouping same in storage areas. Those areas can vary according to the nature of the products being considered (pallets, bins, bags, and so on)., PA1 one or more, for instance two, so called mass storage areas, Z2a and Z2b, as illustrated in FIG. 1, which are intended for keeping products in as small a volume as possible. When several storage areas exist, the products distribution between them may for instance be effected by taking into account their packaging or storage mode (pallets, cases, shelves, and so on), PA1 an order preparing and packing area Z3, which is more directly related to the invention. In this area is effected the so-called "picking" towards a parcel, which can be an intermediate container or directly a cardbox or a crate to be shipped for delivery. Some sorting of initially picked items possibly is executed. Checking the picked items, and closing and labelling the prepared parcels, also are effected in this area Z3, and PA1 a parcel sorting and grouping area Z4, in which said prepared parcels are sorted and grouped according to various parameters such as consignee addresses, carrier addresses, and so on. Finally, the last operation in this area consists of loading such filled parcels into said carrier vehicles. PA1 a picking round being effected with a check list, to be checked off or, in other words, discharged each time a product has been picked and put into the container for preparing an ordered batch; PA1 a picking round being effected with labels and implying adhering said label on the corresponding picked product; PA1 a picking round being directly effected by loading into the batch shipping cardbox, with several lists to be checked off in the case of several parcels per round, one of said lists giving item locations while the others indicate the items for each parcel.
Within the scope of this invention, the notion of parcel should be understood in its broadest sense and the same is true for the notion of container. The latter might be a simple bin which the items corresponding to the batch of customer ordered items are temporarily put into, or a cardboard which will be closed when filled with such a batch, or still a cardboard in a bin.
As regards more particularly the order preparation area Z3, it should be noted that the latter can be included with the storage area or areas Z2a and Z2b, also called picking areas, wherein the picking is effected from cases or other storage containers by means of stackers which allow the operators to pick up items, pieces or other products located in elevated positions. It also, while being included in these Z2a and Z2b, may be located on the lower levels, allowing an easier access to the items to be picked. It still, as a specific preparation area Z4, can be separated from the storage area, as illustrated in FIG. 1.
Otherwise, the prior art provides many order preparation methods. The exemplary, although non exhaustive, following methods which are the most popular can be quoted:
These methods and systems however suffer from the inconvenience of needing many hand operations.
Many attempts certainly were made for mechanizing and automating the picking operations. These attempts however only were successful in very specific economic sectors. Let us mention here the automated distributors for pharmaceutical product distribution.
Mechanizing only in a partial manner also was devised: preparation systems on conveyors with automatic item sorting, or preparation systems with multiple branches, also called order preparation systems with sectors (or with stations).
In these systems, the parcel (cardboard, bin or other, possibly intermediate, container) is carried over to the picking area, wherein products bearing the predetermined references should be picked for parcel filling. As an example, let us consider a system including a plurality of sectors, numbered 1, 2, 3, . . . Suppose that the order comprises several items, but that these items only concern two distinct references, arbitrary labelled A and B. Let us also suppose that the items referenced as "A" are located in sector #2 and the items referenced as "B" in sector #3.
Under these conditions, a parcel to be prepared, which was built up upstream of the system, is carried by a motorized conveyor, and is branched off by a shifting member towards sector #2 without passing through sector #1. This branching is made possible by an identification label (or a similar member) placed on the parcel at initiation time. This label is automatically read at each sector entrance and a shifting member associated with the sector only is actuated if an item stored in this sector should be loaded into the parcel constituting the receiving container.
Generally, the label is provided with bar codes, but other equivalent container codification means also exist (such as for instance a honeycomb reflector, a transponder, an electronic label, and so on).
Once the items available in the sector #2 have been placed into the receiving container for the order being prepared, the operator pushes back such container onto the carrying conveyor, so that it will be directed towards, and enter, the sector #3, and the items with referenced as B will be placed into it. After this loading is completed, the container is pushed back onto the conveyor to be conveyed towards the conveyor line end, without stopping in any other sector since those contain items with references other than A or B.
Although an at least partial operation automation is obtained, the system with many shifting members however suffers from various inconveniences, due to its intrinsic operating mode. Namely, the container transfer, both when branching from the main conveyor towards the sectors and when reverting towards the main conveyor, necessarily is random since the exact batch to be received into each and every container depends upon a given customer's order. Generally, the items related to a particular order are not equally distributed among the various storage sectors. This results in, either unproductive operator waiting times in one or several sectors, or queues of containers to be filled which can exceed the processing ability of one or several sectors, with a possibility of causing, in the worst case, a complete blocking of the installation.
Furthermore, the order preparation uses, either a checklist being associated with a container and pulled out by the operator each time a container branches towards a determined sector, or displays (for instance light emitting screens) being placed on the picking locations in the preparation area and requiring checking off.
In both cases, the prior art suffers from many inconveniences. The checklist must be hand pulled from the container or batch preparation parcel and put back into it. The displays forbid a presence of several operators in a same sector. Finally, these methods do not avoid errors and consequently do not guarantee a large degree of reliability.